Universidad Complutense de Madrid
E-Prints Complutense

The autonomous cycle of near-wall turbulence

Impacto

Downloads

Downloads per month over past year

Jiménez, Javier and Pinelli, Alfredo (1999) The autonomous cycle of near-wall turbulence. Journal of fluid mechanics, 389 (1). pp. 335-359. ISSN 0022-1120

Official URL: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=15223


URLURL Type
http://www.cambridgejournals.org/Organisation


Abstract

Numerical experiments on modified turbulent channels at moderate Reynolds numbers are used to differentiate between several possible regeneration cycles for the turbulent fluctuations in wall-bounded flows. It is shown that a cycle exists which is local to the near-wall region and does not depend on the outer flow. It involves the formation of velocity streaks from the advection of the mean profile by streamwise vortices, and the generation of the vortices from the instability of the streaks. Interrupting any of those processes leads to laminarization. The presence of the wall seems to be only necessary to maintain the mean shear. The generation of secondary vorticity at the wall is shown to be of little importance in turbulence generation under natural circumstances. Inhibiting its production increases turbulence intensity and drag.


Item Type:Article
Uncontrolled Keywords:Boundary-layer; channel flow; streamwise vortices; coherent structures; streak formation; reynolds-number; shear rate; vortex; regeneration; generation
Subjects:Sciences > Physics
ID Code:21856
Deposited On:14 Jun 2013 10:35
Last Modified:12 Dec 2018 15:07

Origin of downloads

Repository Staff Only: item control page